What is the quickest forced mate?

    So this is a game I played a couple of weeks ago with an interesting finish. After my 47th move, my opponent resigned. I can envisage a number of lines where checkmate happens within 8 moves. What do you guys think is the quickest forced mate.?

You can just click the right button to go to the end if the game if you want to skip the game and see what I am talking about.

For the sake of conveniece, the threat of mate comes by way of Rg4#. 

48... Rg4 is mate.

He can slow it down by playing 48. Nh2 or Ne5...Kf5 then you have two options for mate on 49... Rh2 or g4 depending on what he leaves open.

 He could slow it down one more move by losing his Rook on 49. a3...b4xa3 50. he puts his Knight somewhere and 50... you win

Whites best chance is 48 Nxeg...Kxe5  49. Ra3 ...b4xa3

 Draw by stalemate.

I can't see any mate on Rh2 since Kg3 becomes possible when the rook moves away from the g-file. But there will soon be a mate anyway.

I can understand that white resigned. The only way he can avoid an immediate mate with Rg4 is by giving away his pieces. And that will only push the mate some moves away. So that leaves no game play left really for white, except that he could try hoping for a stalemate as pthaloblue suggested, but black would need to be very greedy for that to happen.

Here are some possible variations:

48. Nh2 Kf5 49. Re7 (49. a3 Rxh2+ 50. Kg3 Rg2+ 51. Kf3 e4+ 52. Ke3 Re2#) e4 (black does now NOT yet play 49... Rxh2+? 50. Kg3 Rg2+ 51. Kf3) 50. Rxe4 (50. a3 Rxh2+ 51. Kg3 Rg2+ 52. Kh4 Rg4#) Kxe4 51. a3 Rxh2+ 52. Kg3 Rg2+ 53. Kh4 Rg4#

48. Re7+ Kxf6 49. Nxe5 Kxe7 50. a3 Kf6 51. axb4 Kxe5 52. bxc5 Rg4#

48. Re7+ Kxf6 49. Rxf7+ Kxf7 50. Nxe5+ Ke6 51. a3 Kxe5 52. axb4 Rg4# 

48. Nxe5 Kxe5 49. Re7+ Kf5 50. Re5+ (50. Re3 Rg4#) Kxe5 51. a3 Rg4#

So 48. Nh2 makes it a mate in 6, 48. Re7+ makes it a mate in 5 and 48. Nxe5 makes it a mate in 4. Thus white's best bet is 48. Nh2, but it is rather hopeless for white to say the least.

You could try other variations like 48. Ra6+, but it won't matter. I hope I didn't miss anything. Check it out. 

pthaloblue,

Mate can definitely be delayed longer than move 50. I set up the mating net that you see, so I would have played Rg4# if white gave me the chance. So no stalemate either!

BlueKnightShade,

Nh2 was the line I suspected as the fastest possible forced mate, but the line you listed is flawed. First of all, in your line white has 52. Kg5. Also 50. Rxe4 leads to mate in five:

48. Nh2  Kf5   49. Re7  e4   50. Rxe4  Kxe4   51. a3 (or a4)  bxa3

Now the knight is forced to move and 52. Rg4# is checkmate.

I still think the fastest forced mate is a mate in 8 (including 47...h5):

47...h5  48. Nh2 Kf5  49. Re7 e4  50. Re5+ Kxe5  51. a3 Kf5  52. axb4 Rxh2+

53. Kg3 Rg2+  54.Kh4 Rg4#

Anything faster?

Artist,

Come on, we are from the same country and I still can't understand your language! Anyways, on my 17th move, I took the pawn because it was the easiest way to get an advantage out of the position. After the move, I am a pawn up, my knight is guarded, my pawn structure is still in tact, and my bishop is no longer in jeopardy. After taking the knight on e2, my knight has no more squares, and the bishop is still in jeopardy. In a couple lines (after 17...Nxe2+) I could stay a pawn up, but with a worse pawn structure. What was the line that you saw as better?

I haven't seen anything faster. 

tonightonly7, you have actually posted two questions in this topic. One question is whether there is a forced mate, and the other question is why white resigned. You wrote:

"I realize he was two pawns down and his winning chances were few, but should this have been treated as the killing blow?"

White's concern is not about being two pawns down I would say. White's concern is that there is a check mate threat Rg4# and he can only avoid that mate by losing material. Playing Nh2 is giving the knight away, playing Nxe5 is giving away for a pawn. Giving checks with the rook isn't any better. There is no forced stalemate combination and there are no other tactical possibilities that lead to anything.

Thus it doesn't matter to white whether there is a mate in x moves or not. What matters is that he can't avoid losing material and he can't find any reasonable playing possibilities in the position. The game is over so he resigns.

Some players might not resign because they still have a game going, so no reason for them to resign. But for many players there is nothing sensible they can do in that position, so they don't have a game going anymore. Thus game over - resignation is the only thing that makes sense under those circumstances.

Also: He obviously didn't believe that you would blunder if he tried out playing for stalemate. But it could have been worth going for that since there is nothing to lose. At least that is a plan.

OOPS not as smooth as I saw at first glance.  Still, I understand his choice to resign.  Sorry for the weak reply earlier.  Clearly stalemate is unlikely... I just meant that it's the best thing I see for white as a goal... something to play for.

Congrats' on the win. 

BlueKnightShade

Sorry about the confusion. I changed the question half way through the post. The only question that we haven't answered is 'How fast can mate be forced?' But we probably already answered that as well. If anyone wants to try to find a faster forced mate, that would be cool.
I definitely think that resigning here was reasonable. In a lot of games, I wish my opponents would resign earlier. A few times, I have had to play on for a few weeks after I am something like a pawn and two pieces to the good. In this game, I think that was good timing as far as when to concede defeat.

Pthaloblue and BlueKnightShade,

An opponent is always allowed to try to walk into stalemate and in some cases this is the best plan. There was a daily puzzle last week where the King trapped himself, and forced stalemate. I think that was brilliant and I would have no problem drawing such a game. However, if someone were to try to make me blunder into a stalemate when I am winning (like the proposed line in this post) I would feel slightly insulted. I would not like to play against such an opponent.

At any time in a game there is room for a blunder.  For white to play two moves hoping for the line, "48 Nxeg...Kxe5  49. Ra3 ...b4xa3 Draw by stalemate." seems perfectly acceptable to me.  Yes, you clearly played the stronger game here. However, there are rules about how a game ends... what counts as a win, a draw, and a loss.  For a player to try to turn an almost certain loss into a draw is fine.  Clearly you are the stronger player and you won't make the blunder, but if you do stumble into a stalemate, he deserves the draw- he did nothing wrong. 

 If a player drags out a loss for several weeks with no plan hoping for a miracle draw, that's obnoxious and I will not want to play against them again... but something he sees as a potential two moves out should be playable, and his choice to play that line should be respected.

Hotflow,

I like to make an opponent play to a win also...as long as I still have some winning chances. If my opponent is rated somewhat equally or even lower, I am more likely to play out a lost position. I think everyone expects this though. Making a player rated better than you prove that he can play out a win seems poor etiquette to me.

 I agree, but only in the cases I have listed above. I would only disagree with the above statement if it was a lower rated player trying to get me to blunder into the stalemate. It would still be acceptable per the rules of the game, but I wouldn't be able to help feeling somewhat insulted.

 I definitely agree with you on this account, but you are talking about correspondence chess. I would much prefer the two move attempt at stalemate in one of my games on this site. It would be much quicker and I would either fall for it or I wouldn't. We are not face to face and since we all have screen-names, there are no egos on the line. Earlier, I was referring to over-the-board chess. In an OTB game, where we have shaken hands, know each other's names and ratings, etc., I think it would be a different story.